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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korea Society For Power System Engineering
Journal Basic Information
Journal DOI :
The Korea Society for Power System Engineering
Editor in Chief :
Volume & Issues
Volume 15, Issue 6 - Dec 2011
Volume 15, Issue 5 - Oct 2011
Volume 15, Issue 4 - Aug 2011
Volume 15, Issue 3 - Jun 2011
Volume 15, Issue 2 - Apr 2011
Volume 15, Issue 1 - Feb 2011
Selecting the target year
The Evaluation for Quality Characteristics of Drying Flowering Plant by Vacuum-Freeze
Kim, J.D. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 4, 2011, Pages 5~10
DOI : 10.9726/kspse.2011.15.4.005
In case of using rapid vacuum-freeze drying for high quality dry flower of flowering plant, the morphological and physiological characteristics of dry rose showed as the following. The dry ratio of about 82% presented after 1 day in case of using rapid vacuum-freeze drying and it was reached that the optimum storage water content of general dry products was 18%. The dry ratio of about 89% presented after 4 days. This result indicates very short dry time comparing with natural dry time of 12 days. Also, the morphological characteristics of flowering plant in case of vacuum-freeze drying showed similar shape with real flower. The contraction decreased about 9% comparing with real flower under dry time of 72 hours. But the contraction in case of natural dry decreased 36% and showed noticeable difference. The brightness which affects physiological characteristics of dry flowering plant showed lower values according to the dry process and chromaticity was thick. After 4 days, natural dry was thick with about 2 times comparing with vacuum-freeze drying. In case of vacuum-freeze drying, the quantity of anthocyanin and chlorophyl which affect discoloration and bleaching of dry flowering plant showed the clear difference comparing with natural dry method due to the sublimation by vacuum after rapid freeze with short initial time.
Empirical Design Method for the Damping Force Characteristics of Shock Absorbers
Baek, W.K. ; Kim, C.M. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 4, 2011, Pages 11~18
DOI : 10.9726/kspse.2011.15.4.011
A Shock absorber is one of the most important components in vehicle suspension systems. In general, many repeated analyses are required for the design of a shock absorber to satisfy the suspension characteristics of a specific automobile, like fluid flow analysis and mechanical analysis. The purpose of this study is to develop a fast design tool for shock absorber designers. One of the efficient solutions for this can be an empirical design method considering phenomenological effects from the shock absorber design variables. In order to extract the shock absorber`s experimental characteristics, we used Taguchi method. This method showed that which design variables have major effects for the shock absorber`s damping characteristics. This empirical design method also showed the direction of the design changes to satisfy the designer`s intension.
Evaluation for mechanical hardness of gas turbine rotor bolt according to deterioration of specimen
Gil, D.S. ; Ahn, Y.S. ; Park, S.K. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 4, 2011, Pages 19~24
DOI : 10.9726/kspse.2011.15.4.019
The operational efficiency of domestic gas turbine is about 25% and it is now in the trend of the gradual growth in spite of the severe temperature, frequent starting and shutdown according to the environmental management and the energy-efficient use. Rotor bolts of gas turbine in power plants have been the cause of defects because these gas turbines have been operated for a long time under the high pressure and temperature environment experiencing the aging change and stress concentration of the bonded part. The connection parts of the bolt revealed various failure shape and these parts were elongated under very low pressure when operated in the relaxed condition. The cause is in the lack of the metal distribution in the bottle lack area and the cap screw of the bolt is broken totally in case that the nut is fastened in most cases. Gas turbine rotor bolts are connected to the rotor wheel and these bolts caused the vibration, the bulk accident of the rotor in the event that the coupling power among these bolts was relaxed. Therefore, we would like to evaluate the soundness of the main part of the gas turbine rotor bolt through the measurement of the inner condition change along with the mechanic deterioration and temperature, stress in the gas turbine rotor material.
The Study on image correction of geometric distortion in digital radiography image
Park, S.K. ; Ahn, Y.S. ; Gil, D.S. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 4, 2011, Pages 25~30
DOI : 10.9726/kspse.2011.15.4.025
This study is made to provide with a method for correcting the geometric distortion of the digital radiography image by analytical approach based upon the inverse square law and Beer`s law. This study is aimed to find out and improve a mathematic model of nonlinear type. Variations in the alignment of the X-ray source, the object, and imaging plate affect digital radiography images. A model which is expressed in parameter values; e.g, angle, position, absorption coefficient, length, width and pixel account of radiography source, is developed so as to match the sample image. For the best correction of the digital image that is the most similar to the model image, a correction technique based upon tangent is developed; then applied to the digital radiography images of steel tubes. As a result, the image correction is confirmed to be made successfully.
Durability Evaluation of a Lightweight 40-feet Container Trailer
Kim, J.G. ; Kim, J.Y. ; Yoon, H.J. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 4, 2011, Pages 31~36
DOI : 10.9726/kspse.2011.15.4.031
The need for the lightweight of special vehicle trailer frame is substantially growing due to high gasoline prices and serious environmental issues. In this study, we develop a new lightweight sub-frame for large container trailers and evaluate its durability through a fatigue test. To this end, a reliable three-dimensional parametric finite element model of a sub-frame is constructed and then an optimized lightweight sub-frame is newly developed by using the Taguchi method. Next, we make a trial product of the optimized lightweight sub-frame and conduct a driving test to identify the driving load history at vulnerable areas. Finally, we evaluate the durability of the developed lightweight sub-frame through a fatigue test based on the load history.
The Design & Manufacture and Characteristic Analysis of Eddy Current Sensor for Bolt Hole Defect Evaluation
Ahn, Y.S. ; Gil, D.S. ; Park, S.G. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 4, 2011, Pages 37~41
DOI : 10.9726/kspse.2011.15.4.037
This paper introduces the special eddy current sensor and its characteristic for bolt hole defect evaluation in gas turbine rotor. In the past, Fluorescent penetration inspection method was used for qualitative defect evaluation in gas turbine rotor bolt hole. This method can defect the bolt hole defect but can not evaluate the defect size. Nowadays, eddy current method is used quantitative defect evaluation due to advanced sensor design technology. And eddy current method is more time and cost saving than the old method. We developed bolt shape eddy current sensor for the rotor bolt hole defect detection and evaluation. The eddy current sensor moves to the bolt hole guided by screw nut and detects the defect on the bolt hole. The bolt hole mock-up and artificial defects were made and used for the signal detection & resolution analysis of eddy current sensor. The results show that signal detection capability is enough to detect 0.2 mm depth defect. And the resolution capability is enough to differentiate 02, 0.5, 1.0 and 2.0 mm depth defect.
Frozen and Melting Characteristics of Urea-aqueous Solution for Urea-SCR System by Circulation of Engine Coolant
Choi, B.C. ; Kim, Y.K. ; Kim, H.N. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 4, 2011, Pages 42~47
DOI : 10.9726/kspse.2011.15.4.042
The purpose of this study is to investigate the best melting condition with various winding number of a heating pipe, supplying quantity of engine coolant and coolant temperature at the inlet of the heating pipe. Also, it is to suggest getting method of an appropriate quantity of the agent for the urea-SCR system within 10 minutes. For this matter, this study identifies the temperature distribution of inside of urea-tank while it is frozen at the low temperature condition, and suggests the best melting condition of the frozen urea within 10 minutes. From the results, it was found that 2L of melted urea was obtained by the coolant flow rate of 200L/hr at
for 10 minutes from the start of engine operating.
Design of Thin Plate Type Speed Reducers Using Balls For Robot
Nam, W.K. ; Ham, S.H. ; Oh, S.H. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 4, 2011, Pages 48~53
DOI : 10.9726/kspse.2011.15.4.048
Upon reviewing recent trends for robots, it can be seen that robots are gradually being miniaturized. However, most commercially available speed reducers have limitations in terms of structure and vibration when applied to small robots. In this respect, a tooth profile manufactured using thin plates was designed using balls and data analyzed related to numerical and FEM analysis. The speed reducer was manufactured to check their performance. The manufactured thin plate type speed reducer imposes less compressive stress on its tooth profile and balls, which can greatly increase feasibility.
Study on the Design Program for Non-standard Plastic Gear
Heo, M.B. ; Ham, S.H. ; Nam, W.K. ; Oh, S.H. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 4, 2011, Pages 54~59
DOI : 10.9726/kspse.2011.15.4.054
Currently, plastic gear is widely used as parts of office equipment and industrial machines, because plastic substance has an advantage of light weight and possible to operate in oil-fewer conditions. However, under cyclic loadings, their occurred repetitive deformation due to weak tensile strength and bending stress rather than metal gear. Furthermore, they have a problem of attrition and breakage owing to frictional heat. For solving these problems, when plastic gear`s opponents are metal gear, we should design that plastic gear`s tooth be thick and metal gear`s tooth be thin. In this research, we developed the program which developing tooth profile of non-standard gears automatically and calculating over-pin diameter for inspection after making gear.
Analysis of Fineblanking Forming using CAE
Lee, K.Y. ; Nam, K.W. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 4, 2011, Pages 60~64
DOI : 10.9726/kspse.2011.15.4.060
Computer-aided engineering (CAE) is the broad usage of computer software to aid in engineering tasks. It includes computer-aided design (CAD), computer-aided analysis (CAA), computer-integrated manufacturing (CIM), computer-aided manufacturing (CAM), material requirements planning (MRP), and computer-aided planning (CAP). In this study, the stress of mold analyzed using CAE technique. Punch loads were same difference between 0.5 % and 1.0 % of clearance, but punch load was decreased according to increasing of clearance. Punch load of pre-piercing process worked a little smaller than piercing process. Therefore, the hole of fine blanking process is also more efficient to manufacture the true size after pre-piercing.
Design of a bilinear robust controller for a hydrostatic driver
Park, R.W. ; Cho, S. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 4, 2011, Pages 65~74
DOI : 10.9726/kspse.2011.15.4.065
A Study on the ZnO Supported Silica Gel
Kim, S.Y. ; Kim, M.Y. ; Ju, C.S. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 4, 2011, Pages 75~78
DOI : 10.9726/kspse.2011.15.4.075
There are various types of materials used in electronic industry, such as electrode material, conductor, insulator, anode, cathode and semiconductor. Electrode material type is Cu, Ti, ZnO and so on. Especially if we use mixed ZnO in soil cement or silica gel, we can have advantages in ice road to prevent freezing. We have great impact if we use supported in inorganic substances like silica gel. In this paper we have studied that ZnO supported silica gel and its properties. Zinc acetate dissolved in distilled water were loaded on the silica gel by the reaction with ammonia at
. And we investigated particle structures of ZnO by scanning electron microscopy(SEM) and X-ray diffraction(XRD).